CODEWITHSUNDEEP
javasyntaxgroovy
Travis Webb
Travis Webb

Reputation: 15018

Groovy vs. Java syntax discrepancy

In Java I can do this:

return a
    && b
    && c;

In Groovy, it returns a compile error: unexpected token: &&. It also occurs if I omit the return keyword in Groovy. However if I wrap the statement in parentheses, it works fine.

In all the Groovy resources I've read, I've been told that I should be able to write "straight Java" wherever I want. Is this a bug? If not, what is the reason for this design decision?

I looked here, but did not find this issue listed. I understand that there are some things that cannot be inherited from Java, but this wouldn't seem like one of those things.

Upvotes: 13

Views: 3084

Answers (3)

nate_weldon
nate_weldon

Reputation: 2349

you can do almost all java in groovy except you look at the following.

http://groovy.codehaus.org/Differences+from+Java

if you want to do straight java then you can do it in a *.java class and drop it into the src folder.

Upvotes: 2

Jon Skeet
Jon Skeet

Reputation: 1500465

The problem is that Groovy doesn't require explicit line terminators - and return a looks like a valid statement on its own. You could use:

return a &&
       b &&
       c;

Or use a line continuation:

return a \
    && b \
    && c;

It's not true that all Java is valid Groovy. While most Java syntax is covered, occasionally a feature of Groovy will have an impact on valid Java.

Upvotes: 25

Brendan Long
Brendan Long

Reputation: 54242

Groovy doesn't seem to require semicolons, so I think your code is being intepreted like:

return a;
    && b;
    && c;

From the documentation:

Groovy uses a similar syntax to Java although in Groovy semicolons are optional.

This saves a little typing but also makes code look much cleaner (surprisingly so for such a minor change). So normally if one statement is on each line you can ommit semicolons altogether - though its no problem to use them if you want to. If you want to put multiple statements on a line use a semicolon to separate the statements.

Upvotes: 9

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